Road traffic control systems in which the control transactions are based on video recordings of the traffic at a control station are referred to as “video control systems”. The systems can be used for various control purposes such as, e.g., for controlling the presence of a vehicle in a certain locality to calculate the fee for using this locality in the form of a road toll, zone toll or parking fee, for evidence purposes in the enforcement of speed limits or other traffic violations, for monitoring the compliance with hazardous materials transport regulations, the proper execution of winter road maintenance or street cleaning assignments, fleet vehicles entering and exiting business premises or rental cars entering and exiting car rental facilities, and the like.
Typically, the vehicles are identified based on an optical character recognition (OCR) of the vehicle identification in the recorded images. In practice, the operator of the road traffic control system (in a road toll system: the “Toll Charger,” TC) is not the same entity as the recipient and processor of the control transactions, which is usually the owner of the road traffic control system or a state agency (“Contract Issuer,” CI). For the latter, the validation of the control transactions received from the operator with respect to legitimacy or authenticity is of decisive importance in order to prevent transactions that did not take place from being billed, charged or attributed to the users or persons liable to control.
EP 2 088 568 document discloses a control station that prepares an electronic document with other vehicle recordings and with additional data, e.g., a vehicle identification read by OCR or the detected vehicle type, in case of a violation. Before a prepared document is sent to the central office via a possibly insecure communication link, the document is signed in accordance with a conventional private-public-key process. Although this makes it possible to detect a manipulation on the transmission link, a validation or authentication of the entire control transaction including the document preparation cannot be achieved such that each of the control stations needs to be elaborately secured with additional sensor systems.